wayland: Avoid setting tiled_ xdg-toplevel state

Resizing of tiled GTK apps is broken because GDK relies on some information
provided by the gtk-shell protocol. There is an upstream fix, but it has
not been merged yet.

5.27 is affected too, but unlike 6.0, wayland is not enabled there by default.
So let's disable tiled_ state to fix resizing GTK apps. As far as I know,
GTK is the biggest consumer of tiled_ xdg-toplevel state at the moment, so
hopefully no other apps are going to be affected by this change.